The present invention relates to dry and liquid crop input applicator dispensing systems used in site specific farming. More particularly, the invention relates to a control system for controlling dispensing points on a crop input applicator based on location data, such as that received from a global positioning system (GPS), so that the dispensing points on the applicator are automatically deactivated when the applicator overlaps an area previously treated with crop inputs.
To compete in the global economy, farmers have been forced to become as cost effective as possible. In doing so, farmers have increasingly turned to high technology in the form of site specific farming. Site specific farming involves using global positioning information, coupled with site specific soil or crop data to aid a farmer in applying the correct type of crop inputs in the correct amount at the correct location in a field. To do so, soil or crop data is collected, usually by either soil sampling or some type of sensing, and maps are generated to show the soil and crop conditions of a particular land area or field. These maps aid in determining the amount and placement of crop inputs needed to maximize crop production. Using this information, a farmer can use modern crop input applicators, which are equipped with an on-board computer and a GPS receiver, to apply the crop inputs in precise amounts at the precise desired location.
Liquid and dry air boom type crop input applicators have been used to apply a variety of crop inputs, such as fertilizer, nutrients, seed, and crop protectants, in site specific farming applications. Examples of such applicators are the Terra-Gator.RTM., manufactured by Ag-Chem Equipment Co, Inc., of Minnetonka, Minn., the RoGator.RTM., also manufactured by Ag-Chem Equipment Co, Inc., and the Liqui-Max.RTM., manufactured by Lor*Al Products, Inc., a wholly owned subsidiary of Ag-Chem. While the above vehicles accommodate site specific farming practices, the present inventors have realized that such vehicles, and many other crop input applicators, can be configured to further enhance site specific farming practices.
Site specific farning emphasizes variable rate application of crop inputs. "Application maps" are the blue prints that determine the level and location of crop inputs to be applied to particular management zones in the field. The maps also provide the required variable rate input data necessary to automatically vary input rates using a controller, thereby removing the need for an operator to manually vary the input rates. A limitation of such application maps however, is that each time the planter vehicle or any other type of application vehicle traverses a particular management zone, the associated variable rate input controller will deliver crop inputs in response to the same application map, even if the area was just treated by the controller. In systems capable of creating as-applied maps, the maps dramatically draw attention to the areas in the field that are either skipped or covered twice by overlapping. Multiple applications caused by overlaps are particulary prevalent in irregularly shaped fields and fields with waterways or terraces.
Present methods of eliminating such undesirable overlaps or skips include manual on-off operator control of boom sections or dispensing points. Manual methods are generally inaccurate because they rely on the vehicle operator to determine if the dispensing points are located over a previously applied area and to decide when some or all dispensing points on the crop input applicator must be turned on or off. Such manual methods are made more unreliable due to operator error created by long hours, physical exhaustion, and the sense of urgency under which many operators work. Visibility constraints due to weather, lighting, and dust; variations in operator response times during varying speeds and directions; and errors in judgment all result in undesirable overlaps and skips. Beyond just misapplication of expensive crop inputs, these skips and overlaps also cost farmers in terms of lack of pest or weed control, crop damage, and carry-over crop damage. In addition, when applying chemicals or other types of regulated crop inputs, an overlap may result in areas being over sprayed. Over spray areas are off label, and may even be subject to legal action.
Thus a need exists in the farming industry to provide a crop input applicator vehicle that can reliably activate and deactivate booms, boom sections, planter boxes, drill sections, and individual dispensing points along the applicator in a manner that will prevent multiple applications and skips intentionally or unintentionally created when the applicator covers an area already treated. If such activation were automatic, and not dependent on operators who may be susceptible to error, the applicator control system would be a significant improvement in the art.